Generally, in a manufacturing process of a semiconductor device, photolithography is used to form a fine pattern. Multiple substrates called transfer masks are usually utilized in forming the fine pattern. In miniaturization of a semiconductor device pattern, it is necessary to shorten the wavelength of an exposure light source used in the photolithography, in addition to miniaturization of a mask pattern formed on the transfer mask. Shortening of wavelength has been advancing recently from the use of KrF excimer laser (wavelength 248 nm) to ArF excimer laser (wavelength 193 nm) as an exposure light source in the manufacture of semiconductor devices.
As for the types of a transfer mask, a half tone phase shift mask is known in addition to a conventional binary mask having a light shielding pattern formed from a chromium-based material on a transparent substrate. Molybdenum silicide (MoSi)-based material is widely used for a phase shift film of the half tone phase shift mask. However, as disclosed in Publication 1, it has been discovered recently that the MoSi-based film has a low resistance to exposure light of an ArF excimer laser (so-called ArF light fastness). In Publication 1, ArF light fastness is enhanced by subjecting a MoSi-based film after formation of a pattern under plasma treatment, UV irradiation treatment, or heat treatment to form a passivation film on a surface of the pattern of the MoSi-based film.
Publication 2 discloses a defect repairing technique where xenon difluoride (XeF2) gas is supplied to a black defect part of a light shielding film while irradiating the part with an electron beam to etch and remove the black defect part (defect repair by irradiating charged particles such as an electron beam as above is hereafter simply referred to as EB defect repair). While the EB defect repair was originally used to repair black defects on an absorber film of a reflective mask for EUV lithography, it has recently been used for repairing black defects of a MoSi half tone mask as well.